Easy to use Household Temperature Monitor?

Jim Carroll asks: "I awoke this morning to a gas furnace that conked out. The house was 60F. We had to turn the switch off and on to get it working again. Fair enough -- but I'm worried about it going off when I'm travelling and having the pipes freeze. I'm looking for an inexpensive, simple to use temperature monitor/sensor that would plug into a USB port, that would then log household temperature to a server, so that I can view it through my broadband connection while travelling. Sure, there are all kinds of complex X10 solutions; there seems to be a few kits out there; and some high end industrial applications, but these all involve spending a few hundred dollars. I want simple, straightforward, cheap -- plug it in, and it dumps the temp every few minutes to a file. But there doesn't seem to be anything that is simple, $10-20, that is consumer oriented? And if not, why aren't companies yet making this type of device?"

Comments

Cookies, beer, and a trinket

[ObviousGuy]

If you are away from home for any length of time, ask your neighbor or a family member to stop in once in a while, especially on cold days to make sure that your house is still in good order. Bribe them with cookies and beer, then when you return from your trip give them an exotic trinket from the place you visited.

Also, keep in mind that 60 degrees farenheit is pretty far from freezing and that the inside of your house is unlikely to reach the temperatures required to freeze the pipes *inside* your home.

Re:Cookies, beer, and a trinket

[VultureMN]

I'd think an even more Obvious answer is to have the switch/thermostat fixed. But maybe that's just me...

Re:Cookies, beer, and a trinket

[kinnell]

...and if you really need a geekier solution, have him/her enter the temperature into a text file which you can read remotely over the web.

Re:Cookies, beer, and a trinket

[timshea]

Also, keep in mind that 60 degrees farenheit is pretty far from freezing and that the inside of your house is unlikely to reach the temperatures required to freeze the pipes *inside* your home.

Agreed. 60 degrees Fahrenheit is pretty warm for the inside of a house at night during winter. Even my folks, in their 70s, keep their thermostat at 60 at night.

It's not uncommon that it's in the 50s in my house when I've been lazy with burning wood and it's under 30 outside...and I've slept a few hours too long. Lazy me.

Your pipes aren't likely to freeze until it's well below freezing if you keep your cold water dripping - I see 20s outside and high 40s inside before I need to start letting the water drip in the kitchen, which is the longest run of my water piping.

Now when the power goes out, and your pump stops pumping, then you'd better be home to drain your plumbing before it freezes.

Re:Cookies, beer, and a trinket

[HyperbolicParabaloid]

I'm guessing you don't live anywhere that gets cold.
If your furnace goes off, the thermostat isn't involved, and your house will certainly get cold fast. If it is freezing outside, it WILL get freezing inside. And since the water and heat pipes are in the walls, they will get colder faster than the inside of the house itself (if they are in the exterior walls, that is).
And since it can get pretty damn cold at night, your neighbor would have to move in, and stay awake all the time to provide effective monitoring.

Re:Cookies, beer, and a trinket

[mdielmann]

Also, keep in mind that 60 degrees farenheit is pretty far from freezing and that the inside of your house is unlikely to reach the temperatures required to freeze the pipes *inside* your home.

If he lives in northern U.S, in the Rockies, in Alaska, or any number of places outside the U.S., it is very reasonable to assume that your furnace not working for a day or two will cause your pipes to freeze.

Re:Cookies, beer, and a trinket

[confused one]

And that would have to qualify for most boring web cam on the web.

Use the internal temp monitor in your PC

[dregs]

I am sure with a little bit of work you can figure out ambient temperature by measuring the temperature of your PC CPU. and working out how it compares with the ambient temperature

Re:Use the internal temp monitor in your PC

[acceleriter]

Or run a few Athlons, then it won't matter if the furnace goes out :).

Dallas Semiconductor

[Y Ddraig Goch]

Try Dallas Semicondictor's iButton technology (www.ibutton.com). You should be able to get an iButton evaluation kit for $30-$40 (US). Nice thing about the iButton is that if the power goes off it can still log time/temperature.

Re:Dallas Semiconductor

[CharlieG]

Or go simple, look up aag electronics, by the Temp module (which is iButton) and go from there

Build One?

[semaj]

Why not just put one together with a temperature sensor IC connected to your parallel port? I'm sure there are dozens of simple examples of how to wire them up around.

This site has schematics and the pros and cons of various sensors.

Or...

[mjpaci]

Get an alarm system from ADT. They have all kinds of monitoring as 'value added' services. Things like CO, basement water sensors, temp sensors, fire sensors, smoke sensors, and intruder alert sensors. I'm sure you could build an open source LINUX solution with USB, serial, parallel, and apt-get.

Or, have a neighbor pop over and check once a day.

Just a Thought

[WavyGravy-R5]

One idea would be to buy a thermal monitor for your motherboard, like the after market ones used to stick between your heat sink and cpu. With this, you could plug it into your motherboard, have it go outside of your case, and to the outside air. As far as logging the temperature, you could use Motherboard Monitor 5 for instance, which is free. It can compile all of the statistics, including the temperature you want to record, into a HTML file. Then, just make sure it compiles the folders in a directory you can see, and viola, you'll be able to see your house temperature no matter where you are.

Re:Just a Thought

[mjpaci]

Take WG's suggestion one step further and have your machine call your cell phone every hour if the temp drops below a certain point (say 55 degrees F) until you log in and clear the alert.

space heater

[wowbagger]

There is a fundimental flaw in your idea, which is why no-one has done it:

OK, you have a module plugged into your USB port providing temperature to the computer. Oops, the computer has crashed - now who takes care of the problem?

OK, the computer has rebooted, and sees that it is too cold in the house - the furnace has failed. OK, so now what does the computer do - start crunching SETI@Home packets to heat the place?

OK, the computer emails you. The email goes out, and then the computer picks it up and throws it into your mail queue.

OK, you don't have the computer getting your email - you get it via Webmail. So, your computer is in Ohio, and you are in Hawai'i. Now, what do YOU do about the furnace?

There is already a solution to the problem of keeping your pipes from freezing - it is called an electric space heater. Set it to 45 degrees. Place it in the basement away from any flammable items. If the furnace fails, the heater will automatically keep things from freezing.

Sure, a long term power outage will prevent this from working. Guess what - it would also prevent your computer from working. Yes, a UPS will keep the machine running for a while - how many minutes?

The other solution is even more ingenious - it is called "a neighbor".

Lastly, if you WANT temperature monitoring for your computer - look at Dallas Semiconductor's One Wire system. They have cheap sensors that will report the temperature over 1 wire - a little programming on the parallel port and you can read them.

But really, try the simpler solutions first. They will work better.

Re:space heater

[jjshoe]

OK, you have a space heater that goes up in flames and causes just enough flame for the neighbor watching the house to call the fire department. You now have a broken down door, a basement turned into an ice rink from the water used to put it out. No electricity, and no heat.

My ups ran my fridge for three days in the summer, there is no reason i can think of that it cant handle my computer for a week.

Re:space heater

[cdrudge]

My ups ran my fridge for three days in the summer, there is no reason i can think of that it cant handle my computer for a week.

You never have used a UPS have you? You aren't going to have a UPS that will run your PC for 5-7 days. Well...let me rephrase that. You aren't going to run a regular desktop PC for 5-7 days without spending several thousand dollars on a UPS and batteries. To keep my little OptiPlex GX150 running without my monitor, I'd need one of these and two of these for a little over $2,000 total. And that's just for 48 hours of uptime. At that point, you could just hire a house sitter or just fix the thermostat.

And I doubt you ran a real fridge off of a UPS for 3 days straight, actually used it, and kept food cold.

sump pump

[theIG]

I remember back in september, Tad Truex wrote an article about how he used linux to monitor the sump pump in his basement. He created a small device that made use of Lorentz Force, which he attached to it's power cord, and as he describes, "The voltage induced on the surface of the conductor in this direction is proportional to the magnetic field strength and therefore can be used to detect its strength.
Anyway, he then connected it via a db-9 serial port, and wrote a /proc filesystem driver to create something like
/proc/sump
Which read as either 0 or 1, depending upon weather the sump pump was on or not. Then on his webserver, he wrote some cgi to retrieve /proc/sump's value when a web page was requested, and used that to create a status report page. It was pretty neat, and while I know your problem is a little more complicated, there is a similar solution. It just involves different priciples, and I'm just a lowely programmer.
here is the orriginal article
-kyle

K.I.S.S.

[Spock the Baptist]

Turn on a couple of faucets to drip.

Re:K.I.S.S.

[jpmkm]

I agree. Unless the pipes are fully insulated the entire length, they can freeze regardless of the temperature in the house. A lot of times kitchen sinks are on exterior walls, so those pipes will be the first to freeze.

simple

[f0rtytw0]

step 1: buy something that displays the temperature
step 2: buy a webcam
step 3: place the temperature display in a well lit area and point the webcam at it.

Right tool for the job.

[orangesquid]

The way this has been done for years is to plug a thermistor straight into the joystick port. The PC uses a one-shot astable multivibrator (did I get that right? I always screw up the terminology) which oscillates with a frequency inversely proportional to a resistance, and the period is measured (in software) to determine the resistance. You can then use a lookup table or interpolation curve to get the temperature. Have a process that asks for real time priority (so it doesn't accidentally miscount/mismeasure the hardware data), stick it in crond, and there you go.

I don't know of a USB solution, but what about a USB game port (do such things exist)? Surely they wouldn't be very expensive.

Try this do-dad

[R2.0]

http://www.dataq.com/products/startkit/di194rs.htm

$25 data logger, analog & digital inputs. Use an RTD for temp.

You probably already have a solution.

[chrisatslashdot]

Got a web cam?

Got a thermometer?

Use the motherboard's monitoring ability

[kawika]

A lot of motherboards have a two-pin header where you can attach a thermistor. Here's some how-to on it. Instead of sticking the thermistor to the inside of the PC, run it outside the box. Now you have a PC thermometer. There is plenty of free software like Motherboard Monitor that you can use to grab the temperature from within your own program.

60 ??

[kayen_telva]

we keep the house at 60 all winter. do you actually think 60 is cold ?

Re:60 ??

[Shaleh]

maybe he is married (-: My wife has been complaining non-stop about how low I keep the thermostat. Finally compromised with 64.

Keep it simple and go to the hardware store.

[duffbeer703]

Avoid complex and error-prone geek solutions... buy some pipe wrap insulation and a few electric pipe heating cords.

Pipe cords are like an electric blanket for pipes. They get plugged into a standard wall socket and have a built in thermostat to keep the pipes from freezing. Put these in your bathrooms, kitchen sink and basement and you'll be fine. They run about $10.

Also leave a couple of faucets dripping slightly.

If you are leaving your home for more than a week, ask a friend or neighbor to drop by and check things out.

Re:pipe wrap

[Parsec]

Oops, let me put that in a proper URL.

USB based temp sensor board = $35

[malakai]

I googled for 'usb temp sensor' and this was the 6th results
DLP-TEMP 2-Channel Temperature Acquisition Board

As seen in Nuts & Volts Magazine
Monitor and log digital temperature data from 1 or 2 sensors (one DS18B20 sensor included with purchase of board)
USB 1.1 Compliant
12F629 microcontroller can be reprogrammed with user code (requires programmer)
Rev 2 silicon from FTDI
No in-depth knowledge of USB required
Call or email DLP Design for volume pricing

They provide C++ and VB Code examples. Pretty simple stuff, apparently this will show up as a COM port. The VB code is funny, it has all the c++ code in it commented out and you can see their porting thought process.

good luck